Box moth

Helen L Thomas · August 2022

I have had box moth caterpillars on my box hedge this year for the first time. It has taken 25 years to grow to a lovely hedge full of wildlife. I garden organically and hand picked as many as possible off and cut out the damaged area. The hedge has bounced back but I know this is becoming a big problem in my area. I have a huge lavender hedge planted in the middle of it and haven’t had any reoccurrence despite seeing damage locally and moths in the area. Is this coincidence has the lavender confused the moth or am I just playing a waiting game until the next hit? I would love to hear of others experiences and any organic controls that don’t damage any other wildlife.

Desi_in_London · August 2022

Where in the UK are you based? While the lavender may have helped slightly ( i have lavender near a few bits of box ( took vast majority out due to caterpillars a few years ago), and anecdotally seem to get a bit less than neighbours ( albeit they have longer, better watered stretches of it, and I've left it to fend for itself in its planter , i.e mine basically orange from drought so possibly just a bit crispy for caterpillar food!). This year has been exceptionally bad for box moth ( I had almost none in my neighbourhood last year).

There is a bacteria which affects the caterpillars ( bacillus thuringiensis... can't spell it , BT for short) , various strains , Xentari one brand I am aware of but I believe not available to domestic UK gardeners - ( may still be possible to buy from a netherlands website and perhaps some garden centres here have remaining stock but I don't know). It is approved in the EU, so I assume is a process thing for UK. Quite expensive ( esp if lots of large box hedging)-- it does work, but requires very thorough spraying on an overcast but dry day when there are feeding caterpillars present-- they need to ingest it for it to be effective so needs to be penetrating their webbing protection.-- EDIT TO ADD - Just looked on A...n online and seems to be in stock on the UK site.

In my case if box dies a death I'll just pull it out, its at this point just a mini , somewhat sparse parterre in a (large) planter with a different shrub in the centre.

historyman · August 2022

I too have had Box Moth for the first time this year - I cut all affected areas off and washed the hedge with warm soapy water - yes - it did work now the hedge has recovered and is looking very well

thevictorian · August 2022

I saw a few of the moths here last year but this is the first time it's seemingly reached plague proportions in the area. I don't grow box but it's very popular here and by the start of summer I don't think there was any box that didn't show the tell tale signs of the catipillers. The only ones that seem to have got off more lightly are the large, thick, boundary hedges, all the smaller topiary or short hedges have pretty much been destroyed. Some of the hedges are now resprouting but I hear people talking about a second wave of the moths (although I'm not sure if it's that or the weather killing off the new growth).

Box moth

Posts